Abstract: In order to suppress range sidelobes and improve anti-deception interference performance of conventional radar, a novel waveform transmitting strategy is proposed for conventional radar using nearly orthogonal waveforms. Given a bunch of polyphase coded waveforms with good orthogonality and low range sidelobes, a randomly selected waveform would be transmitted at each transmission. The receiver has the knowledge of the randomly chosen waveform and then can match filtering received signals. Finally, coherent accumulation would be performed for received signals at multiple adjacent transmissions. Both theoretical analysis and numerical results indicate that as range mainlobes can be coherently accumulated while range sidelobes at different transmissions are approximately white, the peak sidelobe level can be suppressed significantly after coherent accumulation.